1. Field of the Invention:
The invention resides in the field of power plants having a buoyant working member motivated by the vertical rise and fall of a surface of a body of fluid and more particularly relates to ocean tide operated devices.
2. Description of the Prior Art:
A number of flotation based prime mover devices including a variety utilizing the energy of the rise and fall of the ocean tides exist in the prior art.
For example, U.S. Pat. No. 3,567,953, Lord, discloses a tide actuated system in which an entire electric generator is mounted on a float vertically moveable with respect to a stationary cable. The up and down movement of the float and generator on the tide with respect to the cable drives the generator. U.S. Pat. No. 3,668,412, Vrana et al., describes a technique in which a float is constrained in a chamber and then released at the height of the tide and additionally the concept of a plurality of such floats and chambers which may be operated on a staggered basis.
Further, U.S. Pat. No. 3,857,242, Gilmore, discloses a non-tidal motor system in which closed containers fall by weight of gravity in air and float upward when transferred to a liquid filled chamber. Similarly, U.S. Pat. No. 3,934,964, Diamond, describes a non-tidal system in which the floation, i.e. displacement volume, of a plurality of cylinders wholly immersed in a body of liquid is controlled by the insertion and withdrawal of a piston in each.
An additional tidal system in which a float is used to increase the potential energy of a pendulum which is then released to generate power is discussed in U.S. Pat. No. 3,011,062, Goldsmith.
All of the prior art tidal systems known to applicant utilize a closed float which falls of its own weight by gravity on the outgoing tide to drive a power generator. Thus in prior art devices, the amount of power which can be produced during the outgoing tide cycle is limited to the potential energy stored in an empty float raised by the incoming tide. In the manner of applicant's invention, this potential energy may be greatly increased by flooding the float with water at a chosen time during the incoming tide. By this method, the weight of a float volume of water is added to the potential energy of the system and becomes available to operate a substantially larger power generator than would otherwise be possible.